This study aims to determine if treatment with an SSRI antidepressant medication, paroxetine, is associated with cellular calcium response to serotonin, platelet serotonin receptors, and improvement in mood in depressed patients with or without hypertension. It is hypothesized that platelets of hypertensive patients with depressive symptomatology with be hyper-responsive to serotonin. Additionally, treatment with an SSRI antidepressant is expected to produce a down-regulation of the serotonin receptor with an associated reduction in platelet cytosolic calcium response as well as improved mood.